The sealskinz mtb thin mid sock with hydrostop is a performance thin weight waterproof mid length sock designed specifically for mtb for conditions where minimal insulation and maximum breathability are required featuring sealskinz unique hydrostop technology which gives you a much more secure fit between your leg and the top of the sock meaning the chance of water ingress through the top is massively reduced constructed with sealskinz proprietary stretchdry waterproof breathable and windpr